Refrigerator panel



Dec. 28, 1965 A. B. MENZER 3,226,150

REFRIGERATOR PANEL Filed March 29, 1963 United States Patent O 3,226,150 REFRIGERATUR PANEL Alfred B. Menzer, Joliet, Ill., assignor to Kemlite Corporation, Joliet, lil., a corporation of Illinois Filed Mar. 29, 1963, Ser. No. 268,866 7 Claims. (Cl. 296-24) This invention relates to a panel for use as a liner in a refrigerator compartment and for other purposes. More particularly the invention relates to a panel to which spacing elements are attached, the spacing elements being effective when the panel is mounted as a liner in a refrigerator compartment to provide an air passage between the liner surface and the articles.

In the construction of refrigerator compartments, whether in railway cars, motor trucks, or stationary structures, it is common that a side wall, for example, contain spaced upright strips or studding, and on the inside of this studding is mounted rigid panels. In the use of the refrigerated compartments, and especially in the case of the mobile compartments, the boxes or other articles which are contained in the compartments are likely to be placed or slide up tight against the liner so that there is no space between the boxes and the liner, and circulating air is shut off, resulting in poor refrigeration of at least part of the contents of the compartment.

To overcome this difficulty it has been common practice to use as the liner of the refrigerator compartments panels which are moulded of plastic material with ribs protruding inwardly from the surface of the panel. Although such moulded plastic panels have desirable surfaces and are satisfactory insofar as providing an air passage one way along the surface of the panel, these panels are expensive to construct and require elaborate and expensive equipment in their manufacture. Further, such panels do not have the rigid support which would be most desirable.

It is therefore an object of this invention to provide a panel which strong and rigid, which is easily and simply manufactured, and which has spacer elements thereon which serve when the panel is positioned as a liner of a refrigerator compartment to preserve an air passage between the refrigerator wall and its contents.

It is a further object to provide such a panel which has a smooth tough surface resistant to abrasion or damage, and which at the same time is rigid and can accept a heavy blow without damage.

Another object is to provide such a panel which has associated with it separate spacer elements which can be simply and easily applied to the panel and which will resist damage or displacement.

Another object is to provide spacer elements of plastic material which can be easily and securely attached to a wall or panel and which though light in weight, are very strong and are of such form as to have maximum resistance to damage from a heavy blow.

Other objects and advantages of the invention will be apparent as the specification proceeds.

The invention is illustrated in the accompanying drawing in which:

FIG. 1 is a schematic View illustrating the manufacture of a rigid coated sheet of improved construction;

FIG. 2 is a perspective view of a part of the interior of a motor truck refrigeration compartment which embodies the improved panel as its liner;

FIG. 3 is an enlarged view showing a preferred form of spacer element as it is about to be secured to the coated sheet, with the sheet being shown in section;

FIG. 4 is an enlarged view similar to FIG. 3 but with the spacer element also shown in section and with the attachment to the sheet fully completed;

3,226,150 Patented Dec. 28, 1965 ICC FIG. 5 is an enlarged broken view showing the form of spacer element illustrated in FIGS. 3 and 4, the view showing the bottom of the element.

My improved procedure for manufacture of the coated rigid sheet is illustrated in FIG. l of the drawing. Refferring to FIG. 1, the character 10 designates a conveyor which is driven in the direction of arrow 11, so that articles resting thereon are passed from left to right. The character 12 designates sheets of plywood which are consecutively placed on the conveyor at the left and are passed through the action of the conveyor toward the right. In such passage the plywood sheets pass first under the shoe 13. Shoe 13 is heated as by an electrical heating element and as the sheets pass thereunder their top surfaces are warmed. As the sheets pass forwardly they next come under the spray heads 14 which are connected with a source of thermo-setting resin under pressure and which are positioned so as to spray downwardly against the heated surface of the sheets giving the sheets a preliminary coat of resin.

I prefer to use plywood as the starting sheet, but may also use solid wood board or other rigid sheet material. Further, I prefer to place on the conveyor a sheet of cellulose film so that the sheets of plywood rest on this film. In FIG. 1 the cellulose film 15 from roll 15a is shown as drawn in the direction of arrow 15b over the conveyor, and the sheets 12 rest on this film as they pass forwardly on the conveyor.

Glass fiber mat 16 is drawn from roll 16a, passed over roll 17 and down into a pool of thermosetting resin 18 contained within the trough 19, passed under the roll 2C', and thence upwardly out of the resin pool, over the roll 21, and then down onto the top surface of the plywood sheets 12.

A sheet of cellulose film 22 is drawn from the roll 23, passed around roll 24 and on the top side of the resin impregnated mat 26 as the assembly of plywood 12 with cellulose film 15 on its under side and resin impregnated glass fiber mat 26 on its top side and cellulose film 22 on top of the resin impregnated film, passes between the squeeze rolls 24 and 25. The squeeze rolls have the function of pressing the layers of this assembly firmly together and squeezing out any air bubbles that may have been entrapped in the resin or between the cellulose films and the other layers of the structure. Another function of the squeeze rolls is to bring the assembly to uniform thickness and leveling out any accumulation or unevenness of the resin.

As the assembly passes along on the conveyor it passes under the shoe 27 which is heated as by an electric current and which imparts heat through the cellulose film 22 to start the cure of the resin, and then passes on under a second shoe 28 which, like shoe 27, also imparts heat through the film 22. The heating elements may be of such number and so spaced that by the time the assembly has passed through all these elements the resin has been fully and finally set. As the cured sheets pass from the conveyor the resin impregnated glass fibers and the cellulose films are cut between panels, and the edges of the panel are trimmed to present a neat appearance. The panels may be shipped in this form with the cellulose films protecting them on both sides and these films stripped off when the panel is about to be used.

The thermosetting resin which is sprayed onto the top of the board at 14, and also the thermosetting resin which is placed in the trough 19 may be any thermosetting resin such as polyester, acrylic, acrylic modified polyester, epoxy resin, or the like. Preferably I use polyester resin with a minor amount of styrene, and preferably I include in the resin dispensed by trough 19 a white or colored pigment which gives a good appearance to the face side of the panel.

When the panel is to be used with spacer elements as referred to herein, the sheets coming off the conveyor I may be drilled with spaced holes. The size of the holes may be, for example, about one fourth inch in diameter. Preferably, the holes are spaced at equal distances apart. The holes may be relatively close together or farther apart, but suitably may be located in staggered rows at about 5 to l5 inches apart in a row with the rows spaced apart likewise.

For use with the drilled sheets so provided, or for other uses, I provide the spacer elements such as is illustrated in FIGS. 3 and 4 of the drawing. In the embodiment shown in FIGS. 3 and 4 the spacer element or knob 30 is moulded of plastic material such as Nylon, polypropylene, polycarbonate, and the like. It has a head portion 3f which is shell like in character having an outer surface 32 which is in the form of a section of a sphere. The wall 33 of the shell-like head 31 is substantially uniform in thickness, and the beveled circular outer edge 34 of this head extends down to and rests firmly upon the surface of the wall or panel 35 to which it is attached. As shown in FIGS. 3 and 4 the wall 35 may be the plywood panel coated with resin impregnated fiberglass produced by the procedure described above. This panel has the wood plies 36, 37 and 38, and on top of these is the resin impregnated fiberglass coating 40. It is provided also with the hole 41 which has been drilled through the panel.

The spacer element 30 has the central internal stem 45 which extends downwardly through the hole 41 and has a portion 46 which extends beyond this hole. Portion 46 has the slots 47 extending axially and at right angles to each other which provide the four prongs 43. Extending throughout the stem 45 is an axial cylindrical opening 49 which is of uniform cross section except at the portion 46 where the cross section diminishes toward the extreme end. Within this axial opening is a pin 50. Before the element is attached to the sheet or wall this pin isin the position shown in FIG. 3 and when it is to be secured this pin is driven downwardly as indicated by arrow 51 to cause its lower end to move into the extended portion 46 and press the prongs 48 outwardly, thus causing the prongs to expand to a larger cross section than the hole 40 and firmly binding the spacer element in place.

One of the knobs or spacer elements 30 may be thus attached at each of the spaced holes 41 in the sheets prepared according to the procedure of FIG. l, and when all the knobs have been attached the completed panel may be utilized in the construction of a refrigerator compartment. Suitably the panels may be mounted edge to edge against the framework of a wall of a refrigerator truck 60 as shown in FIG. 2

Preferably the protective film 22 is removed before the knobs are applied, but such removal is not essential, and the back film may be removed before the panel is mounted, but this removal is less important.

As shown in FIG. 2, a box 70 contained in the refrigerator compartment may be placed up against the side of the refrigerator interior so that a side of the box touches the tops of the knobs 30. Each of the knobs, being of the same size, extends an equal distance from the surface of the panel and each may touch the at side of the box at one point. This structure provides between the surface of the panel sheet and the side of the box a passage through which air may circulate, and the knobs prevent this space from being cut off.

This structure also gives great strength and rigidity to the wall of the compartment. The resin impregnated glass fiber coating on the face of the panel presents a smooth surface which resists rupture while the plywood backing makes for solidity. The knobs 30 also present a smooth surface and are especially resistant to damage. Much strength is provided due to the fact that the outer edges of the knobs rest firmly against the resin impregnated fiberglass coating, and the knob is effectively anchored at its edges against bending or displacement. Still further strength is provided by the shoulder 55 of the upper portion of the stem, which abuts against the top surface of the panel when the knob is in place.

While FIG. 2 shows the improved panel mounted only on one side wall of a refrigerator compartment, it is understood that this panel may be mounted also on the other walls of the compartment, especially the side, end and ceilings of the compartment.

Since the spacer elements or knobs illustrated in each of FIGS. 3 to 5 are hollow they are very light in weight and when mounted on the panel .add very little .t-o the Weight of the complete panel. Furthermore these elements may be fabricated by moulding in large quantities at the factory at relatively low cost. The -coated panels may also be manufactured at the factory, and a practical way of merchandising is to assemble the required number of knobs for one or any desired number of drilled panel-s and ship the panels together with the unassernbled knobs to the point :at which the refrigerator compartments are to be lined -or relined, so that at that point the Iknobs may be secured on the panelswith a hammer in the case of the type of knobs illustrated in FIGS. 3 to 5. The panels, with the knobs attached, may then be mounted on the interior -of the compartment as shown in FIG. 2.

While the foregoing -detailed description and explanation has been concerned with certain specific embodiments of the invention, it is understood .that the invention may take many forms which may vary Widely, all within the spirit and scope of the following claims.

I claim:

1. A refrigerator compartment having on an interior wall thereof a sheet of structural material, :a plurality of rigid knobs which have outer surfaces generally in the form of segments of spheres, such knobs being disposed in spaced relationship substantially uniformly over the front surface of said sheet, individual knobs of said plurality of knobs being spaced both vertically yand horizontally from others of said knobs, means extending from said knobs through said sheet and bearing against the rear surface of said sheet for securing said knobs to said sheet, and a carton within said compartment having one Vof its faces abutting the outer ends of said knobs, said carton, said sheet .and said knobs providing between them a space provi-ding air passages through which .air may pass in vertical and horizontal directions.

2. A refrigerator compartment as defined in claim 1 wherein said knobs are disposed in horizont-ally spaced rows and wherein the knobs in each row are vertically spaced.

3. A panel comprising a single .sheet of structural material having a substantially flat -outer surface, spaced holes in -said sheet which are disposed substantially uniformly over the surface of said sheet, hollow knobs which are shell-like in character having their outer surfaces generally in the form of segments of spheres, the outer Walls of sai-d knobs extending outwardly and downwardly and ending in circular bottom edges which engage said outer surface, said Iknobs having stems which extend centrally of the knobs .and through said holes, said stems having portions which extend beyond the inner Isurface of said sheet, and means for expanding said portions against the edges of said holes :at the inner side of said sheet to secure said knobs and to draw said circular bottom edges into tight engagement with said louter surface.

4. A panel comprising a single sheet of structural material having spaced holes therethrough extending from the front side t-o the rear side of said sheet, spacer knobs `att-ached to said sheet, each of said knobs being equipped with a head portion which is disposed on the front side 4of said sheet, said head portions having bottom edges which bear against the front side of said sheet, said knobs having stems whi-ch extend through said holes, and means .associated with said stems and disposed rearward `of said sheet and bearing against the edge portions of said holes on the rear side of said sheet for securing said stems and holding said edges tightly against the front lside `of said sheet.

5. A panel as set forth in claim 4 in which said bottom edges are beveled downwardly toward the exterior of the knobs whereby sharp circular edges are presented against the outer surface of said sheet.

I6. A panel as yset forth in claim 4 in which said front surface of the sheet is `coated with resin impregnated glass bers, whereby the said bottom edges of the knobs are pressed into tight engagement with said resin impregnated glass fibers.

'7. A panel 4as set forth in claim 5 in which said at surface of the sheet is coated with resin impregnated glass bers, whereby the sharp circular bottom edges of said knobs :are pres-sed into tight engagement with said resin impregnated glass fibers.

References Cited by the Examiner UNITED STATES PATENTS 864,254 8/1907 Perkins 45-131 937,199 /1909 Willard 85-50 1,840,928 1/1932 Anthony 85-84 Jorgensen -137 Steinberger 156-300 Fleischer 45-131 DeRagon 20-2 Sturtevant 296-1 Emmert et al 156-323 Shorts 156-323 Levitt 296-28 Sween 156-300 Petri -84 X Thompson et al. 20-2 Potchen et al 156-323 McBride 296-28 Tenniswood 20-35 Potchen 296-28 Walsh et al. 45-137 Great Britain.

BENJAMIN HERSH, Primary Examiner.

FRANK B. SHERRY, A. HARRY LEVY, Examiners. 

3. A PANEL COMPRISING A SINGLE SHEET OF STRUCTURAL MATERIAL HAVING A SUBSTANTIALLY FLAT OUTER SURFACE, SPACED HOLES IN SAID SHEET WHICH ARE DISPOSED SUBSTANTIALLY UNIFORMLY OVER THE SURFACE OF SAID SHEET, HOLLOW KNOBS WHICH ARE SHELL-LIKE IN CHARACTER HAVING THEIR OUTER SURFACES GENERALLY IN THE FORM OF SEGMENTS OF SPHERES, THE OUTER WALLS OF SAID KNOBS EXTENDING OUTWARDLY AND DOWNWARDLY AND ENDING IN CIRCULAR BOTTOM EDGES WHICH ENGATES SAID OUTER SURFACE, SAID KNOBS HAVING STEMS WHICH EXTENDS CENTRALLY OF THE KNOBS AND THROUGH SAID HOLES, SAID STEMS HVAING PORTIONS WHICH EXTEND BEYOND THE INNER SURFACE OF SAID SHEET, AND MEANS FOR EXPANDING SAID PORTIONS AGAINST THE EDGES OF SAID HOLES AT THE INNER SIDE OF SAID SHEET TO SECURE SAID KBOBS AND TO DRAW SAID CIRCULAR BOTOM EDGES INTO TIGHT ENGAGEMENT WITH SAID OUTER SURFACE. 